Landau-Zener tunneling of qubit states and Aharonov-Bohm interferometry in double quantum wires

Abstract

This paper gives a detailed description of a high-performance tunneling wire “flying qubit” for a quantum mechanical two-level system. We propose a simple double-wire interferometer setup and theoretically carry out the spectroscopy of these flying qubits. As such, we present a tight binding theoretical model which effectively mimicks the experimental setup and then compute the energy diagram and the Landau-Zener quantum tunneling probability under the effect of a sequence of magnetic pulses and gate voltages. At certain critical electrostatic gate voltages, the system exhibits a step rise in the Landau-Zener tunneling transition by playing a multi-crossing scenario in a privileged position of two geometric wires. We predict the consecutive modulations and precise the conservation of the Landau-Zener-Stückelberg-Majorana interference patterns mapped from the two-terminal of the double-wire system. A successful conversion of interferometry signals is identified within the two-path interferometer with higher intrinsic quantum correction errors. The latter is used quantitatively and qualitatively to achieve high-precision measurements beyond the standard Landau-Zener limit. The obtained results confirm the possibility of the construction of Aharonov-Bohm interferometers following the proposed model.